Methods for making styrene copolymers and uses thereof

ABSTRACT

A polymer comprising styrene or substituted-styrene and carboxylated monomer is prepared by a solution polymerization process, comprising first a polymerization step, followed by a neutralization step, and then a distillation step. The polymers have relatively low molecular weights, generally below about 10,000, and can have higher styrene content than has hither been possible. The polymers are found to have good soil release properties and so to be particularly useful in cleaning compositions for fabric or hard surface cleaning.

This application is a division, of application Ser. No. 08/505,436,filed Jul. 21, 1995, now U.S. Pat. No. 5,650,473.

FIELD OF INVENTION

This invention relates to styrene copolymers and concerns a novel methodfor their production and their use in a wide range of compositionsincluding cleaning compositions.

BACKGROUND OF THE INVENTION

European Patent 0 636 687 (National Starch & Chemical Ltd.) describes amethod for the preparation of styrene/acrylic polymers, optionallyincluding a minor amount of n-dodecyl mercaptan (DDM) by a solutionpolymerization process involving polymerization, distillation and thenneutralization steps. Acrylic acid is preferably present in an amount inthe range 50 to 80% by weight, styrene 20 to 50% by weight and DDM up to1% by weight in the resulting polymer product. It is not, however,possible to make polymers with higher styrene content by this process.

U.S. Pat. No. 5,122,568 (American Cyanamid) describes a process forpreparing styrene/acrylic type polymers involving a solutionpolymerization step followed by simultaneous neutralization anddistillation. Not more than 20 weight percent of acid moieties may beneutralized prior to initiation of distillation. The resulting polymershave a weight average molecular weight of at least 30,000 and are usefulin the sizing of paper. Polymers having a styrene:acrylic acid monomerratio of up to 1.4:1 can be prepared in this way.

U.S. Pat. No. 5,326,843 (Rohm and Haas) describes an emulsionpolymerization process for producing alkali-soluble copolymers ofmethacrylic acid and water-insoluble, monoethylenically unsaturatedaromatic monomer such as styrene. The resulting emulsion polymers haveweight average molecular weights in the range 2,000 to 40,000 and caninclude up to about 75% by weight of styrene.

Great Britain Patent 1 107 249 (Johnson) describes a solutionpolymerization process for preparing styrene/acrylic acid and similarpolymers, including use of non-water-miscible solvents such as methylisobutyl ketone, toluene, etc. The polymers have a number averagemolecular weight in the range of 700 to 5,000. The mole ratio of styreneto acrylic acid is in the range 3:1 to 1:1. After reaction, residualsolvent may have to be removed.

SUMMARY OF THE INVENTION

According to the present invention there is provided a solutionpolymerization method of preparing a polymer comprising the polymerizedresidue of a monomer selected from the group consisting of styrene andsubstituted-styrene monomer and a carboxylated monomer, the methodcomprising the steps of (a) polymerizing the styrene and/orsubstituted-styrene monomer and the carboxylated monomer in the presenceof a water-miscible solvent to form a polymer solution containing acidmoieties, (b) neutralizing an amount of the acid moieties in the polymersolution effective to maintain the solubility of the polymer in thepolymer solution throughout the solution polymerization, and then (c)removing the water-miscible solvent from t he polymer solution.

DETAILED DESCRIPTION OF THE INVENTION

By reversing the order of the neutralizaton and solvent removal steps ofthe process as disclosed in EP 0 636 687, it is possible to producestable polymers of higher styrene content (possible comprising up toabout 90% by weight styrene) than has hitherto been possible. The methodis nevertheless applicable to polymers of lower styrene content, as cancurrently be made by conventional techniques.

The method of the invention is also to be contrasted with that of U.S.Pat. No. 5,122,568 in which neutralization and solvent removal arecarried out substantially simultaneously. Surprisingly, it is found byneutralizing the acid moieties prior to solvent removal to a sufficientextent to maintain the solubility of the polymer in the polymer solutionduring the solution polymerization process, particularly during thesolvent removal step, so that further neutralization is not essential,it is possible to produce stable polymers of higher styrene content thanhas hitherto been possible. As noted above, the method is neverthelessapplicable to polymers of lower styrene content.

The proportion of the acid moieties that need to be neutralized in step(b) varies depending on the styrene content of the monomer mix, withhigher proportions being required at higher styrene levels. For polymerscontaining less than about 35 weight of styrene and/orsubstituted-styrene, neutralization may be conducted prior to theremoval of the water-miscible solvent from the polymer solution.However, for polymers containing 40 weight percent or more of styreneand/or substituted-styrene, it has been found that a certain minimumamount of the acid moieties must be neutralized prior to the initiationof the removal of the water-miscible solvent in order effectively tomaintain the solubility of the polymer in the polymer solutionthroughout the remainder of the solution polymerization process. If theminimum effective amount is not neutralized prior to solvent removal,the polymer will become insoluble in the polymer solution during thesolvent exchange, i.e., replacing the water-miscible solvent with waterduring distillation. Once the polymer becomes insoluble, additionalneutralizing base must be added in order to complete the distillationstep. Once armed with the disclosure of this specification, one skilledin the art will be able to determine by experiment the proportion ofacid moiety which must be neutralized prior to removal of thewater-miscible solvent. In all cases, it is preferred to neutralize atleast 30 weight percent of the acid moieties in step (b). Where thestyrene content is in the range 50 to 90 weight percent, at least 50weight percent of the acid moieties are preferably neutralized in step(b), and where the styrene content is in the range 60 to 90 weightpercent, at least 75 weight percent of the acid moieties are preferablyneutralized in step (b).

It is preferred that substantially all of the neutralization takes placeprior to solvent removal so that no further neutralization is required,and in a typical case at least 85% of the acid moieties preferably areneutralized in step (b), provided sufficient neutralization takes placeto maintain polymer solubility during the solvent removal step, andadditional neutralization of "unneutralized" acid moieties may beconducted during or after solvent removal, if desired.

The polymer prepared according to the invention typically comprises atleast 90% by weight of the polymerized residue of the styrene and/orsubstituted-styrene monomer and the carboxylated monomer, with anybalance possibly comprising minor amounts of optional further monomer,e.g., DDM. Such optional monomers may be included to produce a productwith enhanced solubility, or other desired properties.

The styrene or substituted-styrene preferably comprises about 40 to 90%by weight of the total monomer used to prepare the polymer product,preferably 50 to 90%, and more preferably 75 to 90%. As used herein,substituted-styrene is intended to include styrene monomers whereinalkyl groups are substituted either onto the ethylenic chain or thearomatic ring of the styrene molecule. Exemplary substituted-styrenemonomers include alpha-methyl styrene and vinyl toluene.

The carboxylated monomer typically comprises acrylic acid,substituted-acrylic acid, e.g., methacrylic acid, maleic acid orhalf-esters thereof, crotonic acid or itaconic acid, and preferablycomprises about 10 to 60% by weight of the total monomer used to preparethe polymer product, preferably 10 to 50%, and more preferably from 10to 25%.

One preferred polymer product comprises the polymerized residue of atleast 90% by weight of acrylic acid and styrene.

The maximum molar ratio of styrene:acrylic acid achievable by the methodof the invention is about 5:1 on a weight basis. This corresponds toabout 88% styrene and 12% acrylic acid.

The method of the invention enables production of stable liquidpolymers, possibly having higher styrene content than previouslypossible (including the range 75 to 90% by weight).

The invention thus also includes within its scope a polymer produced bythe method of the invention, particularly polymers having greater than75% by weight styrene.

In another aspect the invention provides a polymer comprising styreneand/or substituted-styrene and carboxylated monomer, having a weightaverage molecular weight below about 10,000 and styrene content in therange 75 to 90% by weight.

The polymerization preferably is carried out using one or morewater-miscible solvents, preferably in aqueous solution. Suitablesolvents include low molecular weight alcohols such as methanol,ethanol, propanol, isopropanol, ethers such as dimethyl ether, esterssuch as ethyl acetate and others such as acetone, methyl ethyl ketone.Other suitable water-miscible solvents will be apparent to those skilledin the art. Isopropanol/water mixtures currently are preferred.

Typical physical, and therefore application, properties of the polymersdepend on factors including the ph of the polymer solution and themolecular weight of the polymer solution. It should be noted that thepolymers of the present invention are manufactured in the form ofaqueous solutions.

Below pH 7 the polymers are generally insoluble in aqueous media. Abovethis pH, at pH 7.5 to 8 approximately, polymers containing above about20% acrylate become soluble. Accordingly, the pH of the solutionpolymers preferably are prepared at pH of from about 7 to 9 byneutralizing acid moieties in the polymer solution.

The solubility of the polymers in aqueous media is reduced by increasingthe molecular weight of the polymer, as might be expected. Typicallypolymers of the present invention have weight average molecular weightsin the range about 500 to about 500,000, preferably about 500 to 10,000.

The solubility of the polymer also appears to be strongly affected bythe type of initiator used during the manufacture of the polymer. Themore hydrophobic polymers, typically those containing greater than 60%w/w of styrene can by made using thermal initiators, whereas thosepolymers containing 40 to 60% w/w styrene must be made using only redoxinitiators.

There are certain applications for which polymers with high styrenecontent are desirable. Styrene is hydrophobic and so enhances cleaningproperties of the polymer product. The polymers made by the process ofthe invention have properties that make them useful as ingredients in awide range of compositions.

In a further aspect the present invention thus provides a compositioncomprising a polymer which comprises the polymerized residue of 20 to 90weight percent of a monomer selected from the group consisting ofstyrene and substituted-styrene and 80 to 10 weight percent of acarboxylated monomer, said weight percents based on the weight of thepolymer.

Potential applications for polymer products of the invention include thefollowing:

Dispersants for pigments in aqueous-based paints (silk, gloss) with goodfilm forming

properties and water-resistance.

Dispersants in aqueous inks.

Cement super plasticizers for concrete.

Plasticizers for tile adhesives and grouts.

Film formers in polishes (household and automotive).

Hair fixatives in hairsprays.

Anti-redeposition agents.

Protective colloids.

Emulsion/microemulsion stabilizers.

Calcium scale modifiers.

Corrosion inhibitors.

Polymers in accordance with the invention are unexpectedly found to havesoil release properties, acting to release soil from the surfaces ofmaterials including textiles, skin, hair, metals, plastics, woods,ceramics and other domestic and industrial hard surfaces.

One particularly important application for the polymer products of theinvention is thus as soil release aids in laundry applications andtextile treatments. The polymers are sufficiently hydrophobic to adsorbto cloth during a washing cycle or textile sizing process, yet haveenough hydrophilic character to decrease the hydrophobic nature offabric such as polyester. In particular, the polymers will precipitateonto cloth at pHs at which conventional sizing materials would beremoved. The presence of the polymers will therefore reduce the amountof oily soil that can stick to the cloth. Subsequent washing of thecloth will remove more soil as a result of the reduced interactionsbetween soil and cloth. The polymer product can thus to advantage beincorporated in laundry products and textile treatment products.

The polymers of the invention also find particular application asingredients of cleaning compositions for a wide range of household,institutional and industrial applications, particularly fabric and hardsurface cleaning compositions, such as heavy and light duty liquiddetergents, fabric washing detergents, fabric conditioner products,automatic and manual dishwasher detergents, multi surface cleaners,personal cleaning products, etc.

Such cleaning compositions preferably include non-ionic surfactant,desirably an alcohol ethoxylate. Preferred alcohol ethoxylates have HLB(hydrophobic-lipophilic balance) values between 6 and 20. Examples ofsuch materials are:

    __________________________________________________________________________    HLB       SURFACTANT TYPE               TRADENAME    __________________________________________________________________________     6.9       C.sub.12-14 natural alcohols ethyoxylated with 3 moles of ethylene       oxide                         eg: Empilan KB3     8.1       C.sub.9-11 synthetic alcohols ethyoxylated with 2.5 moles of ethylene       oxide                         eg: Dobanol 91 + 2.5    12.5       C.sub.9-11 synthetic alcohols ethoxylated with 6 moles of ethylene       oxide                         eg: Dobanol 91 + 6    12.0       C.sub.12-15 synthetic alcohols ethoxylated with 7 moles of ethylene       oxide                         eg: Dobanol 25 + 7    12.6       C.sub.12-16 natural alcohols ethoxylated with 8 moles of ethylene       oxide                         eg: Empilan KC8    16.0       C.sub.12-18 natural alcohols ethoxylated with 20 moles of ethylene       oxide                         eg: Empilan KM20    __________________________________________________________________________

Other non-ionic surfactants which may be used include alkylphenolethoxylates, e.g., Ethylan BCP, sorbitan esters, e.g., Span 65,ethoxylated sorbitan esters, e.g., Tween 80, secondary alcoholethoxylates, e.g., Tergitor 15S9 and low foaming modified non-ionicsurfactants such as Plurafac LF131. Surfactant choice is governedprimarily by performance. Lower HLF surfactants are good wetting aidsand emulsifiers whilst higher HLP surfactants are effective assolubilizers and at removing oily and particulate soils. Any of theabove may be selected for use bearing this in mind along with otherproperties such as foaming, stability at various pHs.

A single non-ionic surfactant or a mixture of such surfactants may beused.

A synergistic effect is observed between the polymers and alcoholethoxylates, giving enhanced cleaning and soil removal properties.Alcohol ethoxylates are widely used in cleaning compositions, and thecleaning performance of such compositions can thus be enhanced by addinga suitable amount of the polymer, possibly in place of a proportion ofthe alcohol ethoxylate.

The composition may additionally include other ingredients such as theseconventionally found in cleaning compositions. For example, thecomposition may include one or more anionic surfactants, e.g., sulphatesand sulphonates, provided these are present in an amount by weight thatis less than the amount of non-ionic surfactant. In this context,references to anionic surfactants exclude soaps and amphotericsurfactants.

The polymer is preferably present in cleaning compositions in an amountof from 1 to 10% by weight, more preferably 2 to 5% by weight.

In another aspect the invention provides a method of improving soilrelease properties of a cleaning composition, comprising adding to thecleaning composition 1 to 10 weight percent of a polymer comprising thepolymerized residue of 20 to 90 weight percent of a monomer selectedfrom the group consisting of styrene and substituted-styrene, 80 to 10weight percent of a carboxylated monomer and 0 to 1 weight percent ofDOM, said weight percents based on the weight of the polymer.

The invention also includes within its scope use of the polymercomprising the polymerized residue of 20 to 90 weight percent of amonomer selected from the group consisting of styrene andsubstituted-styrene, 80 to 10 weight percent of a carboxylated monomerand 0 to 1 weight percent of DDM as a soil release agent, particularlyin cleaning compositions.

The invention will be further described, by way of illustration, in thefollowing examples.

EXAMPLE 1

A polymer comprising about 25% by weight acrylic acid, about 75% byweight styrene and up to about 1% by weight DDM was made by thefollowing procedure.

An initial charge of deionized water (140 g) and isopropyl alcohol (240g) was added to a 1 liter glass reactor fitted with the lid which hasinlet ports for an agitator, water cooled condenser and for the additionof monomer and initiator solutions. The reactor contents were heated toreflux (approximately 86° C.).

At reflux continuous additions of monomers (103 g acrylic acid, 297 gstyrene+1 g DDM) and initiator solutions were added to the reactorconcurrently with stirring over 3 hours and 3.5 hours respectively.Initiator solutions were as follows:

    ______________________________________    Catalyst (slow-add 1)    t-butyl hydroperoxide                      40 g    Isopropyl alcohol 20 g    Add over 3.5 hours    Deionized water   20 g    Catalyst (slow-add 2)    Formasul (sodium formaldehyde                      16 g    Add over 3-1/2 hours    sulphoxylate    Deionized water   80 g    ______________________________________

At the end of the initiator slow-addition a 47% aqueous sodium hydroxidesolution (100 g) was added to yield a polymer solution having a final pHof approximately 7 to 8. The reaction temperature was maintained atreflux for a further 1 hour to eliminate any unreacted monomer.

After the 1 hour hold the alcohol co-solvent was removed from thepolymer solution by azeotropic distillation under vacuum. During thedistillation, deionized water was added to the polymer solution tomaintain a reasonable polymer viscosity.

Once the distillation stage has been completed, the aqueous solution ofan acrylic acid/styrene/n-dodecyl mercaptan copolymer was cooled to lessthan 30° C. and transferred to storage.

The resulting product was an aqueous solution of composition givenabove, with a weight average molecular weight of about 750, beingsubstantially non cross-linked and having a solids content of 33.6.Molecular weights in this and the following Example were measured by GPCusing sodium polyacrylate standards.

EXAMPLE 2

A number of further polymers with different ratios of acrylic acidstyrene were made using the method of Example 1. Details of the polymersare given in the following Table, including residual monomer and solventvalues.

    ______________________________________                        Weight average mol                                     No. average mol    Polymer Code             AA:Styrene wt (Mw)      wt (Mn)    ______________________________________    499/23   1:4        Results not accurate    499/24   1:3        Results not accurate    494/13   1:1.7      500          260    H100     1:5.1      7900         1720    400/18   2:1        2780         370    400/19   3:1        3800         680    499/20   4:1        4990         1368    ______________________________________           Residual (% w/w)    Polymer Code             acrylic acid  styrene Isopropanol    ______________________________________    499/23   0.41          0.014   0.147    499/24   0.151         0.001   0.029    494/13   --            0.004   0.29    H100     0.69          0.002   0.001    400/18   0.007         0.001   0.003    400/19   0.008         0.001   0.001    499/20   0.008         0.001   0.001    ______________________________________

Experiments were carried out to test the polymers asemulsion/microemulsion stabilizers, soil release polymers, calcium scalemodifiers, soil removal aids and corrosion inhibitors. Test details andresults are given below.

EXAMPLE 3

Emulsion/Microemulsion Stabilizers

Emulsions were prepared by high shear mixing oils, surfactants, polymerand water at ambient temperature for 15 minutes in order to determinethe ability of the polymers to stabilize oil/water emulsions to modifythe stabilizing performance of a simple laundry surfactant.

a) Hydrophilic Oils, e.g., Octanol

Three series of emulsions of 1, 2, 4, 6 8 and 10% w/w octanol were madein deionized water or 1.0M sodium chloride solution and stabilized with0, 2 or 4% Synperonic A7 (seven mole C₁₃₋₁₅ alcohol ethoxylate)(Synperonic is a trademark). To two of these series, 0.5% w/w activeH100 or 494/13 polymer was added prior to mixing. Stability with timewas observed at ambient and elevated temperature.

Coalescence of oil droplets in emulsions were observed in both deionizedwater and brine on the addition of polymer. The more hydrophobic polymer494/13 gave emulsions with better stability against coalescence. Forexample, a microemulsion of 1% octanol and 2% Synperonic A7 wasdisrupted by the addition of 0.5% w/w active H100 so that a three phasesystem formed comprising of an oil layer, an opaque aqueous layer and aclear lower aqueous layer. In contrast, the addition of 0.5% w/w 494/13to an emulsion of 1% octanol and 4% Synperonic A7 produced a clearmicroemulsion.

b) Hydrophobic oils, e.g., olive oil

20% w/w olive oil emulsion were stabilized with 5 or 10% w/w polymerchosen from 499/24, 23, 18, 19 and 20.

Visual comparison of stability was made after several days using amicroscope.

Emulsions prepared using the higher styrene copolymers 499/22 and 23creamed over the storage period although they showed no tendency tocoalescence (oil separation). Droplet sizes were uniform in both thecream and bulk of the emulsion. These systems were equivalent inperformance to existing surfactant-based systems.

Emulsions prepared using the acrylic-rich copolymer showed an increasein coalescence with increasing acrylic acid content at both levels ofincorporation.

Potential applications of the polymers include the following: asfragrance solubilizers in detergents, as emulsifiers in liquid soaps andskin care formulations, as emulsifiers in cutting fluids (particularlycombined with their anti-corrosive and anti-scaling properties), asemulsifiers in agrochemical formulations, as colloid stabilizers inpolymer latex production in combination with linear alcohol ethoxylatesto replace nonylphenyl ethoxylates, additionally giving improved filingwater resistant properties, as encapsulants for fragrances.

EXAMPLE 4

Corrosion inhibitors, particularly on aluminum

To determine the ability of the polymers to reduce corrosion byadsorption at the surface of metal, the following experiments werecarried out.

A small piece of kitchen foil was placed in a 2% solution of sodiumhydroxide at 60° C. and the time taken for dissolution of the aluminummeasured. Polymer levels were set at 0.1% active.

The following results were obtained.

    ______________________________________              Acrylic Acid:                          Time (mins) taken for foil    Polymer   styrene     to dissolve compatibility    ______________________________________    None-control              --           2.35 (no residues)    499/18    2:1         18:26    499/19    3:1          5:01    499/20    4:1          5:21    499/22    1:3         30:00 + (slight residue formed)    499/23    1:4         30:00 +    ______________________________________

The polymers may therefore have an anti-corrosive effect if incorporatedinto certain laundry products and can be used to replace highly alkalinesilicates, e.g., in automatic dishwashing powders. The anti corrosiveproperties mean the polymers may also be useful in other applicationsincluding in cutting fluids, surface coatings, e.g., paints, lacquers;as fixatives in aqueous hairsprays giving reduced can corrosion.

EXAMPLE 5

Scale modifiers/calcium binders

Measurements of calcium binding capacity were made on H100 and 494/13using the Hampshire Test. Both polymers had low binding capacities (43.7mg and 33.8 mg CaCO₃ per g of polymer) compared to homopolymers ofacrylic acid of a similar molecular weight (about 320 mg CaCO₃ per g ofpolymer).

The acrylic-rich polymers do exhibit some ability to prevent theformation calcium scale under dynamic test conditions, making themuseful additives for a number of detergent and industrial applications.

Results:

    ______________________________________                    % scale inhibition at a dose    Polymer         of 10 ppm active polymer    ______________________________________    499/18           40.7%    499/19           73.0%    499/20           96.8%    499/24          <5%    ______________________________________

EXAMPLE 6

Enhancing wash performance:

As both high and low styrene-containing polymers have stronginteractions with non-ionic alcohol ethyoxylate surfactants inelectrolyte solution, they can be used to increase the soil removalperformance of the surfactants under wash conditions. The soil removalfigures of polymer and surfactant combinations are higher than thefigures for polymer or surfactant alone and therefore the combinationsare strongly synergistic.

Wash conditions

Temperature: 40°or 60° C.

Wash liquor: 13.51

Water hardness: 250 ppm CaCO₃

Cloth: Polyester:cotton soiled with pigment/sebum wfk 20C and 20D

Different detergent doses were used as follows:

1. 1.2 g/l Synperonic A7

0.8 g/l Sodium carbonate

2. 1.2 g/l Synperonic A7

0.8 g/l Sodium carbonate

0.25 g/l 494/13 polymer

3. 1.2 g/l Synperonic A7

0.8 g/l Sodium carbonate

0.25g/l H100 polymer

4. 0.8 g/l Sodium carbonate

0.25 g/l H100 polymer

5. 0.8 g/l Sodium carbonate

Details of the wfk test cloths used are:

    ______________________________________    Cloth Code             Type           Soil Type    ______________________________________    wfk 20D  Polyester/cotton (65:35)                            synthetic pigment + synthetic                            sebum    wfk 20C  Polyester/cotton (65:35)                            synthetic pigment + lanolin    ______________________________________

The cloths are supplied by wfk Forschungsinsitute, Krefeld, Germany.

RESULTS

    ______________________________________                   Reflectance                           Reflectance                   wfk 20C wfk 20D    ______________________________________    Washes at 40° C.    1. No polymer    43.7      61.8    2. 494/13        44.0      66.4    3. H100          44.7      65.6    4. No surfactant 37.0      46.6    5. No polymer or surfactant                     36.7      46.6    Standard deviation ˜2 reflectance units.    Washes at 60° C.    1. No polymer    52.0      63.4    2. 494/13        59.5      70.2    3. H100          59.0      69.9    4. No surfactant 38.0      46.4    5. No polymer or surfactant                     38.0      46.2    ______________________________________

In the above tables, higher reflectance figures indicate lighter andhence cleaner cloths.

Combinations of polymer and alcohol ethoxylate can be usedcost-effectively to replace more expensive surfactants in fabricpowders, hard surface cleaners, metal scourers, etc.

EXAMPLE 7

Soil Release Aids:

The ability of the polymers to absorb to cloth during the wash cycle ofa household washing machine to give a soil-repellent coating wasdetermined as follows:

Using a commercially available compact powder (without polycarboxylates,enzymes, bleaches and anionic surfactants) containing 4% of eachpolymer, cotton swatches were washed 3 times at 60° C. in 250 ppm CaCO₃hardness water. Detergent dose was 5 g/l. Half of the swatches were thensoiled with a 1:1 olive oil:red iron oxide mixture, allowed to conditionand then washed with the unsoiled swatches for a further 3 times in thesame detergent formulation. Soil removal from the dirty cloth andtransfer to the unsoiled cloth was assessed by reflectance measurementand percent soil removal values calculated.

RESULTS

    ______________________________________                 % soil removal                 from soiled                            Redeposition onto unsoiled    Polymer dosed at 4%                 cloth      cloth (Reflectance)    ______________________________________    Control-no polymer                 11.4       83.5    (4% sodium sulphate)    499/19       23.1       85.3    499/20       26.6       86.1    499/24       13.2       86.4    ______________________________________

Polymers may be used in heavy duty fabric washing powders, duringtextile production as anti-soiling agents, in surface coatings.

6. Examples of formulations

a) Model laundry Powder:

    ______________________________________    Ingredient          % Active    ______________________________________    Zeolite 4A builder  25    Sodium carbonate    15    Sodium citrate      10    Alcohol ethoxylate (7 mole EO)                        12    Acrylic:styrene copolymer                        4    Sodium disilicate   3    Sodium palm kernel fatty acid                        3    Sodium carboxymethyl cellulose                        0.3    Fragrance           0.3    Sodium sulphate     to balance    ______________________________________

The properties of the polymers mean they additionally have advantageswhen used for soil dispersancy, scale modification, to enhance primarysoil removal, as anti-soiling agents, as fragrance encapsulating agentsfor oxidizable ingredients, as corrosion inhibitors.

b) Hard-surface bathroom cleaner:

    ______________________________________                   % w/w active                              % w/w active    Ingredient     A          B    ______________________________________    Dobanol 25 + 9 7.00       7.00    Tetrasodium EDTA                   --         2.00    Potassium carbonate                   4.00       4.00    Dowanol DPM    --         5.00    Polymer 499/18 1.00       --    Water          to balance    ______________________________________

Dobanol 25+9 is a C₁₂₋₁₅ synthetic alcohol ethoxylated with 9 moles ofethylene oxide (Dobanol is a trademark). Tetrasodium EDTA is tetrasodiumethylene diamine tetracetate, and acts as a sequestrant for calcium.Dowanol DPM is the solvent dipropylene glycol monomethyl ether and isavailable from Dow Chemical (Dowanol is a trademark).

Formulation B was prepared as a control and the performance of bothformulation A and B compared to a commercially-available bathroomcleaning trigger spray, denoted formulation C. Use of polymer allowsremoval from such formulations of solvent and potentially harmful EDTAwhilst improving overall performance with economy benefits.

i) Calcium scale dispersancy. i.e., ability to prevent scale deposits

One percent solution was titrated with 44 g/l of calcium acetatesolution at pH 10. Turbidity was measured with increasing volume ofcalcium acetate added.

    ______________________________________               Turbidity (NTU) vs volume of calcium               acetate added (cm.sup.3)lt    Formulation  2     4    ______________________________________    A            7.4   750    B            4.6   solution too turbid to measure    C            3.5      4.0    ______________________________________

ii) Spray patterns using standard trigger spray:

There were no apparent differences between the 3 formulations.

iii) Foam tests: rapid decay preferable to reduce need for rinsing

    ______________________________________    Formulation              Decrease in Foam Volume over 15 minutes    ______________________________________    A         20 cm.sup.3    B          8 cm.sup.3    C         90 cm.sup.3    ______________________________________

The polymer thus aids foam collapse resulting in reduced rinsing beingrequired.

iv. Cloudpoint measurements: stability at elevated temperatures:

    ______________________________________    Formulation   Cloud Point °C.    ______________________________________    A             53    B             53    C             53    ______________________________________

All formulations have suitable stability at 40° C. Over periods ofstorage formulation B shows slight phase separation.

v) Particulate soil dispersancy: reduce redeposition of soil:

Iron oxide was dispersed with 0.5% detergent in hard water at pH 7.5 andallowed to settle. Turbidity was then measured at a fixed distance fromsurface.

    ______________________________________    Formulation   Turbidity, NTU    ______________________________________    A             2.6    B              0.55    C             1.2    ______________________________________

iv) Detergency:

Aluminum surface soiled with 0.5 g of an iron oxide and olive soil,conditioned at 40° C. was sprayed in vertical position with a fixedvolume of each formulation. The surface was rinsed with water andderived at 70° C. The percentage soil removal determined by weightdifference of soiled and washed surface. The procedure was repeated toestablish accuracy.

RESULTS

    ______________________________________    Formulation   % soil removed    ______________________________________    A             5.2    B             5.8    C             7.8    ______________________________________

EXAMPLE 8

The polymers are also useful in dishwasher products. A base automaticdishwasher powder from the literature was prepared and polymersincorporated at 4% w/w. The formulation was as follows:

    ______________________________________    Ingredient           % w/w active    ______________________________________    Sodium carbonate     20.0    Sodium citrate dihydrate                         12.5    Zeolite 4A           7.5    Polymer or polymer mixture post added                         4.0    Sodium silicate (2.4:1)                         7.0    Sodium perborate tetrahydrate                         5.0    Plurafac LF131 surfactant                         2.0    Sodium sulphate      to 100%    ______________________________________

Highball tumbler glasses were then artificially soiled with a 4:1margarine:dried milk powder and washed over two cycles in a householddishwasher in 250 ppm CaCO₃ water using formulation.

Once dry, the glasses were inspected visually for salt spotting (whiterings) and fat filming. Any such residues indicated that the washingprocess has been incomplete.

Controls used were:

1. Powder+4% sodium sulphate

2. Powder+4% acrylic+maleic copolymer mol weight 70,000 (Narlex MA 340,Narlex is a trademark)

3. Powder+2% Narlex MA340+2% mol weight 5,000 homopolymer of acrylicacid, (Alcosperse 602N, Alcosperse is a trademark)

4. 4% Alcosperse 602N

5. A commercially available phosphate-built powder

Styrene copolymers tested were 499/18. 499120 and 499/24 all at 4.0% w/wand then at levels of 2% w/w with 2% Nadex MA340.

Results were as follows:

With control 1, organic filming and many white spots were observed.

With control 2, filming was prevented but some spotting evident.

With Control 3, again no filming but some spotting.

With Control 4, filming was absent but some spots were visible.

With Control 5, spotting and filming was eliminated. Glasses were clear.

With 4% 499/18, no filming, some limited spotting.

With 4% 499/20, no filming, fewer spots than with 499118.

With 4% 499/24, some spots but noticeable filming.

With 2% 499/18+2% MA340, very few spots and no filming. Glasses wereclear.

With 2% 499/20+2% MA340, very few spots and no filming. Glasses wereclear.

Overall, the use of mixtures of acrylic+maleic carboxylates and higheracrylic acid containing styrene copolymers gave better wash results thancombinations of acrylic+maleic polymers and low molecular weightpolyacrylic acid polymer. Performance of the former combination wasclose of that of a conventional phosphate-built product, currently underscrutiny on environmental grounds.

EXAMPLE 9

70% acrylic acid (AA) 30% styrene (all are % wtw's)

To a 2 liter glass reactor fitted with a water condenser, paddle stirrerand thermometer were added 240 g of deionized water and 240 g of IPA.This sealed flask was heated to reflux temperature (86° C.). At reflux amonomer solution comprising 298 g AA, 102 g styrene and 1 g dodecylmercaptan (DDM) and redox initiator solution of 1. deionized water 20 g,IPA 20 g and tertiary butyl hydrogen peroxide (TBHP) and 2. deionizedwater 80 g and formasul (SFS) 16 g were added concurrently, the monomersolution being added over 3 hours and the redox initiator solutionsbeing added over 3.5 hours, maintaining reflux throughout. At the end ofthe additions the batch was held at reflux temperature for a further 1hour.

At this point the batch was split into two equal portions A and B.

A. To 520 g of polymer solution 150 g of 47% caustic solution (85%)neutralized) was added with stirring with all of the solvents stillpresent. (This amount caustic was chosen to give a final polymer pH ofapprox pH=7, although if desired all of the acid groups could beneutralized to give a final polymer pH-approx 9). The polymer solutionwent from clear to slightly opaque but no polymer precipitated out ofsolution. The batch was then stripping to remove the IPA cosolvent andwater was added as a diluent.

The final polymer solution in water after all the cosolvent had beenremoved had a solids content of 41.2%, pH-7.1 and the polymer solutionwas transparent.

B. 200 g of deionized water was added to 520 g of the polymer solutioncontaining cosolvents. A total of 230 g of distillate was removed fromthe polymer solution to remove all of the alcohol cosolvent. The polymersolution was then neutralized with 150 g of caustic solution to give atransparent polymer solution with solids=42.6% and pH=7.0.

EXAMPLE 10

60% acrylic acid (AA) I 40% styrene (all are % w/w's)

To a 2 liter glass reactor fitted with a water condenser, paddle stirrerand thermometer were added 240 g of deionized water and 240 g of IPA.This sealed flask was heated to reflux temperature (86°C.). At reflux amonomer solution comprising 255 g AA, 170 g styrene and 1 g dodecylmercaptan (DDM) and redox initiator solution of 1. deionized water 20 g,IPA 20 g and tertiary butyl hydrogen peroxide (TBHP) and 2. deionizedwater 80 g and formasul (SFS) 16 g were added concurrently, the monomersolution being added over 3 hours and the redox initiator solutionsbeing added over 3.5 hours, maintaining reflux throughout. At the end ofthe additions the batch was held at reflux temperature for a further 1hour.

At this point the batch was split into two equal portions A and B.

A. To 520 g of polymer solution 120 g of 47% caustic solution (85%neutralized) was added with stirring with all of the solvents stillpresent. The polymer solution went from clear to very slightly hazy butno polymer precipitated out of solution. The batch was then stripped toremove the IPA cosolvent and water was added as a diluent.

The final polymer solution in water after all the cosolvent had beenremoved had a solids content of 36.1%, pH=7.2 and the polymer solutionwas transparent.

B. 200 g of deionized water was added to 520 g of the polymer solutioncontaining cosolvents. A total of 230 g of distillate needed to beremoved from the polymer solution to remove all of the alcoholcosolvent. After 220 g of distillate had been removed the polymer hadsubstantially dropped out of solution preventing further stripping. Atthis point 120 g caustic was added with deionized water. The polymerredissolved back into solution and stripping was continued to give atransparent polymer solution having solids content 36.1%, pH=7.2. Thepolymer solution was then neutralized with 150 g of caustic solution togive a transparent polymer solution with solids=42.6% and pH=7.0.

EXAMPLE 11

50% acrylic acid (AA)/ 50% styrene (all are % w/w's)

To a 2 liter glass reactor fitted with a water condenser, paddle stirrerand thermometer were added 240 g of deionized water and 240 g of IPA.This sealed flask was heated to reflux temperature (86° C.). At reflux amonomer solution comprising 212 g AA, 212 g styrene and 1 g dodecylmercaptan (DDM) and redox initiator solution of 1. deionized water 20 g,IPA 20 g and tertiary butyl hydrogen peroxide (TBHP) and 2. deionizedwater 80 g and formasul (SFS) 16 g were added concurrently, the monomersolution being added over 3 hours and the redox initiator solutionsbeing added over 3.5 hours, maintaining reflux throughout. At the end ofthe additions the batch was held at reflux temperature for a further 1hour.

At this point the batch was split into two equal portions A and B.

A. To 520 g of polymer solution 106 g of 47% caustic solution (85%neutralized) was added with stirring with all of the solvents stillpresent. The previously opaque polymer solution went transparent, i.e.,the polymer became totally soluble in the cosolvent mixture and nopolymer precipitated out of solution. The batch was then stripped toremove the IPA cosolvent and water was added as a diluent.

The final polymer solution in water after all the cosolvent had beenremoved had a solids content of 33.8%, pH-7.4 and the polymer solutionwas transparent.

B. 200 g of deionized water was added to 520 g of the polymer solutioncontaining cosolvents. A total of 230 g of distillate needed to beremoved from the polymer solution to remove all of the alcohol cosolventafter 150 g of distillate had been removed the polymer had substantiallydropped out of solution preventing further stripping. At this point 106g caustic was added with deionized water. The polymer redissolved backinto solution and stripping was continued to give a transparent polymersolution have solids content 32.9%, pH=7.5.

EXAMPLE 12

40% acrylic acid (AA)/ 60% styrene (all are % w/w's)

To a 2 liter glass reactor fitted with a water condenser, paddle stirrerand thermometer were added 240 g of deionized water and 240 g of IPA.This sealed flask was heated to reflux temperature (86° C.). At reflux amonomer solution comprising 170 g AA, 225 g styrene and 1 g dodecylmercaptan (DDM) and redox initiator solution of 1. deionized water 20 g,IPA 20 g and tertiary butyl hydrogen peroxide (TBHP) and 2. deionizedwater 80 g and formasul (SFS) 16 g were added concurrently, the monomersolution being added over 3 hours and the redox initiator solutionsbeing added over 3.5 hours, maintaining reflux throughout. At the end ofthe additions the batch was held at reflux temperature for a further 1hour.

At this point the batch was split into two equal portions A and B.

A. To 520 g of polymer solution 80 g of 47% caustic solution (85%neutralized) was added with stirring with all of the solvents stillpresent. The previously opaque polymer solution went transparent, i.e.,the polymer became totally soluble in the cosolvent mixture and nopolymer precipitated out of solution. The batch was then stripped toremove the IPA cosolvent and water was added as a diluent.

The final polymer solution in water after all the cosolvent had beenremoved had a solids content of 30.9%, pH=7.5 and the polymer solutionwas transparent.

B. 200 g of deionized water was added to 520 g of the polymer solutioncontaining cosolvents. A total of 230 g of distillate needed to beremoved from the polymer solution to remove all of the alcoholcosolvent. After 76 g of distillate had been removed the polymer hadsubstantially dropped out of solution preventing further stripping. Atthis point 80 g caustic was added with deionized water. The polymerredissolved back into solution and stripping was continued to give atransparent polymer solution having solids content 30.5%, pH=7.5.

EXAMPLE 13

30% acrylic acid (AA)/ 70% styrene (all are % w/w's)

To a 2 liter glass reactor fitted with a water condenser, paddle stirrerand thermometer were added 240 g of deionized water and 240 g of IPA.This sealed flask was heated to reflux temperature (86° C.). At reflux amonomer solution comprising 102 g AA, 298 g styrene and 1 g dodecylmercaptan (DDM) and redox initiator solution of 1. deionized water 20 g,IPA 20 g and tertiary butyl hydrogen peroxide (TBHP) and 2. deionizedwater 80 g and formasul (SFS) 16 g were added concurrently, the monomersolution being added over 3 hours and the redox initiator solutionsbeing added over 3.5 hours, maintaining reflux throughout. At the end ofthe additions the batch was held at reflux temperature for a further 1hour.

At this point the batch was split into two equal portions A and B.

A. To 520 g of polymer solution 54 g of 47% caustic solution (85%neutralized) was added with stirring with all of the solvents stillpresent. The previously opaque polymer solution went transparent, i.e.,the polymer because totally soluble in the cosolvent mixture and nopolymer precipitated out of solution. The batch was then stripped toremove the IPA cosolvent and water was added as a diluent.

The final polymer solution in water after all the cosolvent had beenremoved had a solids content of 29.5%, pH=7.5 and the polymer solutionwas transparent.

B. 200 g of deionized water was added to 520 g of the polymer solutioncontaining cosolvents. A total of 230 g of distillate needed to beremoved from the polymer solution to remove all of the alcoholcosolvent, after 45 g of distillate had been removed the polymer hadsubstantially dropped out of solution preventing further stripping. Atthis point 54 g caustic was added with deionized water. The polymerredissolved back into solution and stripping was continued to give atransparent polymer solution having solids content 28.7%, pH-7.7.

EXAMPLE 14

50% acrylic acid (AA)/ 50% styrene (all are % wlw's)

To a 2 liter glass reactor fitted with a water condenser, paddle stirrerand thermometer were added 240 g of deionized water and 240 g of IPA.This sealed flask was heated to reflux temperature (86° C.). At reflux amonomer solution comprising 212 9 AA, 212 g styrene and 1 g dodecylmercaptan (DDM) and redox initiator solution of 1. deionized water 20 g,IPA 20 g and tertiary butyl hydrogen peroxide (TBHP) and 2. deionizedwater 80 g and formasul (SFS) 16 g were added concurrently, the monomersolution being added over 3 hours and the redox initiator solutionsbeing added over 3.5 hours maintaining reflux throughout. At the end ofthe additions the batch was held at reflux temperature for a further 1hour.

At this point the batch was split into two equal portions A and B.

A. To 520 g of polymer solution 38 g of 47% caustic solution (20%neutralized) was added with stirring with all of the solvents stillpresent. The previously opaque polymer solution remained opaque, i.e.,the polymer did not fully solubilize in the cosolvent mixture. Nopolymer precipitated out of solution. The batch was then stripped toremove the IPA cosolvent and water was added as a diluent.

The final polymer solution in water after all the cosolvent had beenremoved was viscous and opaque and became solid on cooling.

B. To 520 g of polymer solution 25 g of polymer solution 25 g of 47%caustic solution (30% neutralized) was added with stirring with all ofthe solvents still present. The previously opaque polymer solutionremained opaque, i.e., the polymer did not fully solubilize in thecosolvent mixture. No polymer precipitated out of solution. The batchwas then stripped to remove the IPA cosolvent and water was added as adiluent.

The final polymer solution in water, after all the cosolvent had beenremoved, was viscous and opaque and became solid on cooling.

EXAMPLE 15

40% acrylic acid (AA)/ 60% sytrene (all are % wiw's)

To a 2 liter glass reactor fitted with a water condenser, paddle stirrerand thermometer were added 240 g of deionized water and 240 g of IPA.This sealed flask was heated to reflux temperature (86°C.). At reflux amonomer solution comprising 170 g AA, 255 g styrene and 1 g dodecylmercaptan (DDM) and redox initiator solution of 1. deionized water 20 g,IPA 20 g and tertiary butyl hydrogen peroxide (TBHP) and 2. deionizedwater 80 g and formasul (SFS) 16 g were added concurrently, the monomersolution being added over 3 hours and the redox initiator solutionsbeing added over 3.5 hours maintaining reflux throughout. At the end ofthe additions the batch was held at reflux temperature for a further 1hour.

At this point the batch was split into two equal portions A and B.

A. To 520 9 of polymer solution 20 g of 47% caustic solution (20%neutralized) was added with stirring with all of the solvents stillpresent. The previously opaque polymer solution remained opaque, i.e.,the polymer did not fully solubilize in the cosolvent mixture. Nopolymer precipitated out of solution. The batch was then stripped toremove the IPA cosolvent and water was added as a diluent. Some polymerprecipitated out of solution during the distillation making theremainder of the distillation step problematic.

The final polymer solution in water, after all the cosolvent had beenremoved, was opaque and semi-precipitated. The batch became solid oncooling.

B. To 520 g of polymer solution 30 g of 47% caustic solution (30%neutralized) was added with stirring with all of the solvents stillpresent. The previously opaque polymer solution remained opaque, i.e.,the polymer did not fully solubilize in the cosolvent mixture. Nopolymer precipitated out of solution. The batch was then stripped toremove the IPA cosolvent and water was added as a diluent. Some polymerprecipitated out of solution during the distillation making theremainder of the distillation step problematic.

The final polymer solution in water, after all the cosolvent had beenremoved, was opaque and semi-precipitated. The batch became solid oncooling.

What is claimed:
 1. A cleaning composition comprising an alcoholethoxylate surfactant having a HLB of 6 to 20, and 1 to 10 weightpercent, based on the total weight of the cleaning composition, of awater-soluble polymer having a molecular weight of from about 500 toabout 10,000, wherein the polymer is prepared by solution Polymerizationand comprises the residue of(a) 20 to 90 weight percent, based on theweight of the polymer, of a monomer selected from the group consistingof styrene and substituted-styrene; and (b) 80 to 10 weight percent,based on the weight of the polymer, of a carboxylated monomer which isselected from the group consisting of substituted or unsubstitutedacrylic acid, methacrylic acid, maleic acid, the half esters of maleicacid, crotonic acid, itaconic acid, and combinations thereof.
 2. Acleaning composition comprising an alcohol ethoxylate surfactant havinga HLB of 6 to 20, and 1 to 10 weight percent, based on the total weightof the cleaning composition, of a water-soluble polymer having amolecular weight of from about 500 to about 10,000, wherein the polymeris prepared by solution polymerization and comprises the residue of(a)20 to 60 weight percent, based on the weight of the polymer, of amonomer selected from the group consisting of styrene andsubstituted-styrene; and (b) 40 to 80 weight percent, based on theweight of the polymer, of a carboxylated monomer which is selected fromthe group consisting of substituted or unsubstituted acrylic acid,methacrylic acid, maleic acid, the half esters of maleic acid, crotonicacid, itaconic acid, and combinations thereof, wherein the polymer isprepared by solution polymerization using a redox initiator.